instance method _quote

# File activerecord/lib/active_record/connection_adapters/abstract/quoting.rb, line 100
      def _quote(value)
        case value
        when String, ActiveSupport::Multibyte::Chars, Type::Binary::Data
          "'#{quote_string(value.to_s)}'"
        when true       then quoted_true
        when false      then quoted_false
        when nil        then "NULL"
        # BigDecimals need to be put in a non-normalized form and quoted.
        when BigDecimal then value.to_s('F')
        when Numeric, ActiveSupport::Duration then value.to_s
        when Date, Time then "'#{quoted_date(value)}'"
        when Symbol     then "'#{quote_string(value.to_s)}'"
        when Class      then "'#{value}'"
        else
          "'#{quote_string(YAML.dump(value))}'"
        end
      end